There is known a hydro-turbine installation, comprising two turbines horizontally and coaxially mounted in a conduit and one electro-generator (Inventor Certificate SU No 1280178, issued 30 Dec. 1986).
In the aforesaid installation, the coaxial shafts of turbines are longitudinally aligned along the conduit, and connected via a multiplying gear, placed in a hermetic capsule situated in the center of the conduit, to a vertical shaft of the generator mounted outside of the conduit. This, however, leads to inefficient use of energy of the water stream running through the cross-section of the conduit. It is conditioned by the fact that the turbines (in this case of a propeller type), operate in different periods of time, depending on the direction of the stream, and that the capsule with the gear partially blocks the stream directed along the shafts.
The closest prior art to the present invention in terms of its structure and achievable result is a power unit, comprising two coaxially mounted orthogonal turbine with blades of a hydro-dynamical profile and a three-phase linear electro-generator, the shafts of the turbines are aligned across the fluid stream, the blades are oriented in the opposite direction in relation to each other providing opposite rotation of the turbines, irrespective of the direction of the stream, and the electro-generator is located between the turbines (Patent RU2245456, issued on 20 Nov. 2003).
However the design of the aforementioned generator assumes the use of wheel supports fixing a vertical clearance between elements of the linear generator, and the inductors of the generator are joined by power electric cables supported by flexible members and mounted on the central pylon where the cables are connected to power output terminals (electric power takeoff rings). The use of the movable elements leads to a decrease of reliability of the power unit.